The molar formation enthalpy of nano-SiO2 with different surface area

Three samples of silicon dioxide were syhthesized and their surface areas were measured. A thermo-chemical cycle was designed to calculate the molar formation enthalpy. The molar formation enthalpy, ΔfHmΦ, for three amorphous silica with the Langmuir surface area 198.0854, 25.1108 and 11.9821 m2 g−1 gave −895.52, −910.86 and −915.67 kJ mol−1, respectively. With the increasing surface area, the values of ΔfHmΦ increased accordingly.The results …